Reverse Engineering The IBM PC110, One PCB At A Time

There’s a dedicated group of users out there that aren’t ready to let their beloved IBM PC110 go to that Great Big Data Center in the Sky. Unfortunately, between the limited available technical information and rarity of replacement parts, repairing the diminutive palmtops can be tricky.

Which is why [Ahmad Byagowi] has started a project that aims to not only collect all the available schematics and datasheets that pertain to the machine, but to reverse engineer all of the computer’s original circuit boards. Working from optical and x-ray scans, the project has already recreated the motherboard, power supply, modem, keyboard, and RAM module PCBs in KiCad.

Just last week the project released production-ready Gerbers for all the boards, but considering there have been 45+ commits to the repository since then, we’re going to assume they weren’t quite finalized. Of course, with a project of this magnitude, you’d expect it to take a few revisions to get everything right. (Hell, we’ve managed to screw up board layouts that had fewer than a dozen components on them.)

If you’d like to lend a hand, [Ahmad] says he could use the help. Beyond checking the boards for problems and reporting issues, he’s also on the hunt for any datasheets or other documentation that can be found for the PC110 or its components. It looks like there’s still schematic work that needs to be done as well, so if your idea of zen is figuring out how ~30 year old computers were wired up internally, this might be the perfect summer project for you.

Interestingly, our very own [Arya Voronova] has been working on creating a drop-in replacement motherboard for the Sony Vaio P using KiCad and imported board images. That hobbyists are now able to do this kind of work using free and open source tools is a reminder of just how far things have come in the last few years.

Thanks to [adistuder] for the tip.

Card's author typing on the IBM PC110's keyboard, with the Pico W-based card plugged into the PCMCIA slot on the left. PC110's screen shows successful ping 8.8.8.8.8.

Pi Pico W Does PCMCIA, Gets This IBM PC110 Online

Bringing modern connectivity to retro computers is an endearing field- with the simplicity of last-century hardware and software being a double-edged sword, often, you bring a powerful and tiny computer of modern age to help its great-grandparent interface with networks of today. [yyzkevin] shows us a PCMCIA WiFi card built using a Pi Pico W, talking PCI ISA. This card brings modern-day WiFi connectivity to his IBM PC110, without requiring a separate router set up for outdated standards that the typical PCMCIA WiFi cards are limited by.

The RP2040 is made to talk PCI ISA using, of course, the PIO engine. A CPLD helps with PCI ISA address decoding, some multiplexing, and level shifting between RP2040’s 3.3V and the PCI 5 V levels. The RP2040 software emulates a NE2000 network card, which means driver support is guaranteed on most OSes of old times, and the software integration seems seamless. The card already works for getting the PC110 online, and [yyzkevin] says he’d like to improve on it – shrink the design so that it resembles a typical PCMCIA WiFi card, tie some useful function into the Pico’s USB port, and perhaps integrate his PCMCIA SoundBlaster project into the whole package while at it.

This is a delightful project in how it achieves its goal, and a pleasant surprise for everyone who’s been observing RP2040’s PIO engine conquer interfaces typically unreachable for run-of-the-mill microcontrollers. We’ve seen Ethernet, CAN and DVI, along many others, and there’s undoubtedly more to come.

We thank [Misel] and [Arti] for sharing this with us!